The Indirect Impact of Flooding on the Road Transport Network: A Case Study of Santar\'em Region in Portugal

Abstract

The indirect impacts of flooding on transportation networks include, among others, consequences of the service disruption for the users. Indirect impacts are of a wider scale and with a longer incidence in time than direct impacts. The key aspect for the quantification of indirect impacts of flooding is the assessment of the disruption of the transportation service, with social and economic consequences. In this work, a traffic model for a pilot zone is constructed for accurate quantification of the functionality of the network after the failure of infrastructure components such as road segments and bridges. A mesoscopic simulation, which is capable of building a road network model, assigning trip paths with the impact of road closures, and evaluating travel time and vehicle volume redistribution in a given disruption scenario, was used to identify the traffic disruption in the face of flood events. Modelling outputs from a case study in the Santarém region of Portugal indicate which roads are more congested in a day. A comparison between the baseline and a flood scenario yields the impacts of that flood on traffic, estimated in terms of additional travel times and travel distances. Therefore, simulating and mapping the congestion can largely facilitate the identification of vulnerable links.

Assessing Flood Indirect Impacts on Road Transport Networks Applying Mesoscopic Traffic Modelling: The Case Study of Santarém, Portugal

“…Previous studies have addressed the potential impacts for transportation networks during flood events, but the impacts of flood disruption may persist long after the flood has subsided, which also needs to be considered. This paper, as an extension of the published investigations of the authors regarding this case study [30], contributes to the existing literature by applying a deeper look and valid alternative modelling into the flooded road network. The mesoscopic simulation was used to build the road network model, assigning trip paths with the impact of road closures and speed reductions, and evaluating travel time and travel distance after the failure of infrastructure components such as roads and bridges because of a flood event in a specific case study.…”